You can remove the media card and see if it makes a difference with the BlackBerry problem.

Your problem could also be the battery. It may be worthwhile to try another battery, a genuine BlackBerry battery that you know is good. Borrowing one would be preferable in case it isn't the battery.

If you have dropped the BlackBerry or got it wet, that would be first guess on cause of the problem.

As far as malware on the media card, while a possibly a danger to other systems that may use the card, I doubt that could be causing the rebooting problem on the BlackBerry. Still, you need to remove the malware (if it is there).Posted via BlackBerryForums.com Mobile